OTTAWA—Federal officials have quietly warned operators of electrical grids, transportation hubs and other key infrastructure of the cyberthreat from insiders who could unleash devastating viruses and cripple systems, internal government notes reveal.

Crucial networks that Canadians rely on for everyday needs face a “substantial threat” from rogue employees out to wreak digital havoc, warn the Public Safety Canada briefing notes.

“The insider threat is difficult to detect and can cause real damage.”

No special hacking skills are required, just a portable memory key loaded with a malicious code. As a result, it is important that organizations have the right security protocols and procedures, “for example by limiting access to systems only to those who genuinely need it.”

A federal briefing on the insider threat was delivered last December to leaders of the 10 most crucial infrastructure sectors, the notes say.

They point out that over 90 per cent of critical infrastructure — key to delivering everything from food and clean water to banking and health services — is controlled by the private sector and all of it is dependent in one way or another on information technology to operate. Many critical infrastructure sectors are interdependent, meaning a problem in one could have a “cascading impact” in others.

The notes, prepared earlier this year for Monik Beauregard, a senior assistant deputy minister at Public Safety Canada, were obtained by The Canadian Press under the Access to Information Act.